The genetic data of MICA microsatellite were obtained by genotyping 577 samples in 13 population groups of China, which are Han-YN, Han-GD, Han-SD, Bai, Dai, Lahu, Li, Naxi, Sala, She, Tu, Wa and Zang-YN, with genescan. Five alleles have been observed in the population groups, which are A4, A5, A5.1, A6 and A9. A5 allele is the most frequent in all population groups except Lahu and Li, while the most frequent allele for Lahu and Li is A5. 1 and A4 respectively. The second most frequent allele is the A5.1 in Han-YN, Han-SD, Dai, Naxi, Sala, She, and Wa. The lest frequent allele for Han-YN, Han-GD, Lahu, Naxi, She, Wa is the A6 which is not observed in Li. A4 allele is the lest frequent in Han-SD, Bai, Dai, Sala, Tu, Zang-YN. The results show that the distribution of MICA microsatellite is different in these population groups, and the polymorphism information contents (PIC) of this microsatellite is high. It is a potential useful marker in the study of human origin and migration, personal identification, gene mapping and location, and disease diagnosis.